| Message ID | 20220907045907.484043-6-ndesaulniers@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix debug info for asm and DEBUG_INFO_SPLIT | expand |
On Wed, Sep 7, 2022 at 1:59 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > Dmitrii, Fangrui, and Mashahiro note: > > Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2. > > Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g > specified in order for -gsplit-dwarf to work at all. > > -gsplit-dwarf has been mutually exclusive with -g since support for > CONFIG_DEBUG_INFO_SPLIT was introduced in > commit 866ced950bcd ("kbuild: Support split debug info v4") > I don't think it ever needed to be. > > Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@gmail.com/ > Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@mail.gmail.com/ > Link: https://reviews.llvm.org/D80391 > Cc: Andi Kleen <ak@linux.intel.com> > Reported-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> > Reported-by: Fangrui Song <maskray@google.com> > Reported-by: Masahiro Yamada <masahiroy@kernel.org> > Suggested-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> > Reviewed-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > --- > Changes v2 -> v3: > * Pick up Nathan's RB tag. > > Changes v1 -> v2: > * Add reference to 866ced950bcd, cc Andi, in commit message. > > scripts/Makefile.debug | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug > index 2845145c1220..c20f8f2e76bf 100644 > --- a/scripts/Makefile.debug > +++ b/scripts/Makefile.debug > @@ -1,10 +1,4 @@ > -DEBUG_CFLAGS := > - > -ifdef CONFIG_DEBUG_INFO_SPLIT > -DEBUG_CFLAGS += -gsplit-dwarf > -else > -debug-cflags-y += -g > -endif > +DEBUG_CFLAGS := -g > > debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 > debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 > @@ -15,6 +9,8 @@ ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) > KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) > endif > > +debug-flags-$(CONFIG_DEBUG_INFO_SPLIT) += -gsplit-dwarf > + This patch changes the behavior that is not mentioned in the commit log. Previously, -gsplit-dwarf was passed only when compiling *.c files. (DEBUG_CFLAGS). Now it is passed also when compiling *.S files. (debug-flags-y is appended to KBUILD_AFLAGS) Please confirm if this makes sense, and if so, please mention it in the commit log. As far as I tested, I did not see this change was useful. When *.S is compiled to *.o, *.dwo is also created, but it does not contain any debug info. > ifdef CONFIG_DEBUG_INFO_REDUCED > DEBUG_CFLAGS += -fno-var-tracking > ifdef CONFIG_CC_IS_GCC > -- > 2.37.2.789.g6183377224-goog >
On Sat, Sep 10, 2022 at 5:56 AM Masahiro Yamada <masahiroy@kernel.org> wrote: > > On Wed, Sep 7, 2022 at 1:59 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > > > Dmitrii, Fangrui, and Mashahiro note: > > > > Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2. > > > > Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g > > specified in order for -gsplit-dwarf to work at all. > > > > -gsplit-dwarf has been mutually exclusive with -g since support for > > CONFIG_DEBUG_INFO_SPLIT was introduced in > > commit 866ced950bcd ("kbuild: Support split debug info v4") > > I don't think it ever needed to be. > > > > Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@gmail.com/ > > Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@mail.gmail.com/ > > Link: https://reviews.llvm.org/D80391 > > Cc: Andi Kleen <ak@linux.intel.com> > > Reported-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> > > Reported-by: Fangrui Song <maskray@google.com> > > Reported-by: Masahiro Yamada <masahiroy@kernel.org> > > Suggested-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> > > Reviewed-by: Nathan Chancellor <nathan@kernel.org> > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > > --- > > Changes v2 -> v3: > > * Pick up Nathan's RB tag. > > > > Changes v1 -> v2: > > * Add reference to 866ced950bcd, cc Andi, in commit message. > > > > scripts/Makefile.debug | 10 +++------- > > 1 file changed, 3 insertions(+), 7 deletions(-) > > > > diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug > > index 2845145c1220..c20f8f2e76bf 100644 > > --- a/scripts/Makefile.debug > > +++ b/scripts/Makefile.debug > > @@ -1,10 +1,4 @@ > > -DEBUG_CFLAGS := > > - > > -ifdef CONFIG_DEBUG_INFO_SPLIT > > -DEBUG_CFLAGS += -gsplit-dwarf > > -else > > -debug-cflags-y += -g > > -endif > > +DEBUG_CFLAGS := -g > > > > debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 > > debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 > > @@ -15,6 +9,8 @@ ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) > > KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) > > endif > > > > +debug-flags-$(CONFIG_DEBUG_INFO_SPLIT) += -gsplit-dwarf > > + > > > This patch changes the behavior that is not mentioned in the commit log. > > > > > Previously, -gsplit-dwarf was passed only when compiling *.c files. > (DEBUG_CFLAGS). > > Now it is passed also when compiling *.S files. > (debug-flags-y is appended to KBUILD_AFLAGS) > > > Please confirm if this makes sense, and if so, > please mention it in the commit log. > > > > As far as I tested, I did not see this change was useful. > > When *.S is compiled to *.o, *.dwo is also created, > but it does not contain any debug info. > > > > > ifdef CONFIG_DEBUG_INFO_REDUCED > > DEBUG_CFLAGS += -fno-var-tracking > > ifdef CONFIG_CC_IS_GCC > > -- > > 2.37.2.789.g6183377224-goog > > > > > -- > Best Regards > Masahiro Yamada BTW, you do not need to resend the entire series even if you end up with v4. - 01-02 - 03 - 04-05 are mutually independent of the others now. They can be reviewed separately. -- Best Regards Masahiro Yamada
diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug index 2845145c1220..c20f8f2e76bf 100644 --- a/scripts/Makefile.debug +++ b/scripts/Makefile.debug @@ -1,10 +1,4 @@ -DEBUG_CFLAGS := - -ifdef CONFIG_DEBUG_INFO_SPLIT -DEBUG_CFLAGS += -gsplit-dwarf -else -debug-cflags-y += -g -endif +DEBUG_CFLAGS := -g debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 @@ -15,6 +9,8 @@ ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) endif +debug-flags-$(CONFIG_DEBUG_INFO_SPLIT) += -gsplit-dwarf + ifdef CONFIG_DEBUG_INFO_REDUCED DEBUG_CFLAGS += -fno-var-tracking ifdef CONFIG_CC_IS_GCC
Dmitrii, Fangrui, and Mashahiro note: Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2. Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g specified in order for -gsplit-dwarf to work at all. -gsplit-dwarf has been mutually exclusive with -g since support for CONFIG_DEBUG_INFO_SPLIT was introduced in commit 866ced950bcd ("kbuild: Support split debug info v4") I don't think it ever needed to be. Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@gmail.com/ Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@mail.gmail.com/ Link: https://reviews.llvm.org/D80391 Cc: Andi Kleen <ak@linux.intel.com> Reported-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> Reported-by: Fangrui Song <maskray@google.com> Reported-by: Masahiro Yamada <masahiroy@kernel.org> Suggested-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> --- Changes v2 -> v3: * Pick up Nathan's RB tag. Changes v1 -> v2: * Add reference to 866ced950bcd, cc Andi, in commit message. scripts/Makefile.debug | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)